File content as of revision 2:293665548183:

/**
 * Demo program for BiQuad and BiQuadChain classes
 * author: T.J.W. Lankhorst <t.j.w.lankhorst@student.utwente.nl> and Matthijs and Roy and Dion
 */
#include "mbed.h"
#include "HIDScope.h"
#include <stdlib.h>
#include <iostream>
#include <iomanip>
#include <complex>
#include "BiQuad.h"


AnalogIn    emg0( A0 );
AnalogIn    emg1( A1 );
DigitalIn   button1(PTA4);

Ticker      sample_timer;
Ticker      cal_timer;
HIDScope    scope( 2 );
DigitalOut  led(LED1);
//DigitalOut  led2(LED_GREEN);                  

double S[50];
double meanSum = 0;

//Filter toevoegen, bestaande uit notch, high- en lowpass filter
BiQuadChain Notch;
//50 Hz Notch filter, for radiation from surroundings

//Notch filter chain for 100 Hz
BiQuad bqNotch1( 9.75180e-01, -1.85510e+00, 9.75218e-01, -1.87865e+00, 9.75178e-01 );
BiQuad bqNotch2( 1.00000e+00, -1.90228e+00, 1.00004e+00, -1.88308e+00, 9.87097e-01 );
BiQuad bqNotch3( 1.00000e+00, -1.90219e+00, 9.99925e-01, -1.89724e+00, 9.87929e-01 );

//Notch filter chain for 50 Hz
BiQuad bq1( 9.87512e-01, -1.95079e+00, 9.87563e-01, -1.96308e+00, 9.87512e-01 );
BiQuad bq2( 1.00000e+00, -1.97533e+00, 9.99919e-01, -1.96726e+00, 9.93522e-01 );
BiQuad bq3( 1.00000e+00, -1.97546e+00, 1.00003e+00, -1.97108e+00, 9.93951e-01 );

//15 Hz Highpass filter, as recommended by multiple studies regarding EMG signals
//BiQuad Highpass15(9.35527e-01, -1.87105e+00, 9.35527e-01, -1.86689e+00, 8.75215e-01);

//2Hz Highpass
BiQuad Highpass1(9.91154e-01, -1.98231e+00, 9.91154e-01, -1.98223e+00, 9.82385e-01);


//20 Hz Lowpass
BiQuad Lowpass100( 3.62168e-03, 7.24336e-03, 3.62168e-03, -1.82269e+00, 8.37182e-01 );

//450 Hz Lowpass filter, to remove any noise (sample frequency is only 500 Hz, but still...)
//BiQuad Lowpass450(8.00592e-01, 1.60118e+00, 8.00592e-01, 1.56102e+00, 6.41352e-01);

void sample()
{
    /* Set the sampled emg values in channel 0 (the first channel) and 1 (the second channel) in the 'HIDScope' instance named 'scope' */
    //scope.set(0, emg0.read() );
    //scope.set(1, fabs(Notch.step(emg0.read())) );
    scope.set(0, fabs(Highpass1.step(Lowpass100.step(Notch.step(emg0.read())))) ); 

    for (int i=1;i < 50; i++) {
            S[i] = S[i-1];    
            meanSum = meanSum + S[i];    
        }
    S[0] = fabs(Highpass1.step(Lowpass100.step(Notch.step(emg0.read()))));
    double mean = meanSum / 50;
    scope.set(1, fabs(4*Highpass1.step(Lowpass100.step(Notch.step(emg0.read())))));
    meanSum = 0;
    /* Repeat the step above if required for more channels of required (channel 0 up to 5 = 6 channels) 
    *  Ensure that enough channels are available (HIDScope scope( 2 ))
    *  Finally, send all channels to the PC at once */
    scope.send();
    /* To indicate that the function is working, the LED is toggled */
    led = !led;
}

void calibration()
{
    //function to determine maximal EMG input in order to allow motorcontrol to be activated
    double maxsignal = 0;
    if (button1.read() == false){
        for (int n = 1; n < 5000; n++){ //calibrate for 5000 samples or 10 seconds
            double signalfinal = fabs(Highpass1.step(Lowpass100.step(Notch.step(emg0.read()))));
            if (signalfinal >= maxsignal){
                maxsignal = signalfinal; //keep changing the maximal signal
            }
        }
    }
}

int main()
{   
    //Constructing the notch filter chain
    Notch.add( &bqNotch1 ).add( &bqNotch2 ).add( &bqNotch3 ).add( &bq1 ).add( &bq2 ).add( &bq3 );
   
    /**Attach the 'sample' function to the timer 'sample_timer'.
    * this ensures that 'sample' is executed every... 0.001 seconds = 1000 Hz
    */
    sample_timer.attach(&sample, 0.001);
    cal_timer.attach(&calibration, 0.002);//ticker to check if motor is being calibrated

    /*empty loop, sample() is executed periodically*/
    while(true) {
    
    
    }

}